Oxygen evolution reaction(OER)is a bottleneck half-reaction in many important energy conversion processes(e.g.,water splitting),and one of the key issues lies to develop high-efficiency,cost-effective OER electrocatal...Oxygen evolution reaction(OER)is a bottleneck half-reaction in many important energy conversion processes(e.g.,water splitting),and one of the key issues lies to develop high-efficiency,cost-effective OER electrocatalysts.Rather than those popular extrinsic modulations of any catalysts with gradually degraded performance,we aim at the utilization of the intermediates offered from the undergoing OER as long-standing electrocatalysts.Herein,by inverted design,we extracted the bimetallic borides(FeCoB_(2))-derived intermediates metal borates in the OER,unlocking their potential as a selffunctionalized highly active catalytic phase in-situ formed on the metal boride surface for continuing OER operation.Mechanistically,the surface metal atoms are oxidized to oxyhydroxides,and the surface metalloids(B)are further transformed to the corresponding oxoanions to form metal borates.Such OER self-produced electrocatalyst exhibits a small overpotential of 295 mV at 10 mA/cm2 and its high catalytic activity lasts even after 200 h.Compared with FeCoB_(2),the catalytic activity of this electrochemically activated FeCoB_(2) is~7 times higher.The in-situ formed metal borate is dominatingly responsible for the obtained high catalytic activity.Such unique OER-produced self-functionalization surfaces of metal borates afford to greatly reduce the energy barrier of the continuing OER,thereby accelerating the reaction process.展开更多
Based on the thermokinetic theory, a novel thermokinetic research methodself-function regression method, which could be used to determine the kinetic parameters k1, k2 and k-1 of the complex reaction: B+ ...Based on the thermokinetic theory, a novel thermokinetic research methodself-function regression method, which could be used to determine the kinetic parameters k1, k2 and k-1 of the complex reaction: B+ , ,was proposed in this paper. The kinetics of the reaction of ascorbic acid (H2A) with hydrogen peroxide was investigated at pH=57 and T=298.15 K, and the kinetic parameters k1, k 2 and k-1 were obtained with this method. The kinetics of the reaction was investigated in detail. The kinetic parameters of the oxidation of ascorbic monoanion (HA-) and ascorbic dianion (A2-) with hydrogen peroxide were 3.33×10-3 s-1and 25.48 s-1 at 298.15 K, respectively. The molar enthalpy change for the reaction was -554.64 kJ·mol-1 in phosphate buffer solution at pH 7 and at 298.15 K.展开更多
As a multifunctional fluorescent nanomaterial, carbon dots (CDs) not only have small size, stable chemical properties, excellent photoluminescence characteristics, but also exhibit good biocompatibility and low toxici...As a multifunctional fluorescent nanomaterial, carbon dots (CDs) not only have small size, stable chemical properties, excellent photoluminescence characteristics, but also exhibit good biocompatibility and low toxicity. It has attracted considerable attention in the field of nanotechnology and biological science. CDs contain abundant functional groups on the surface, which not only retain part of the properties of raw materials, but also may have new photoelectric, catalytic, biomedical, and other functions. In this review, we systematically summarize the synthesis methods, modifications, optical properties, and main biological functions of CDs in recent years. The application of functionalized modified CDs in biological detection, biological imaging, photodynamic therapy, photothermal therapy, targeted therapy, drug delivery, gene delivery, protein delivery, and other biomedical fields is introduced. The latest progress of CDs with its own biomedical function in antioxidant, anti-pathogen, and disease treatment is summarized. Finally, we discuss some problems in the practical application of CDs and look forward to the future development trend of self-functional CDs combined with surface modification to achieve multimodal treatment of diseases.展开更多
基金Financially supported by the National Natural Science Foundation of China(51872115,52101256,51932003)China Postdoctoral Science Foundation Project(2020M680043)+1 种基金Science and Technology Research Project of the Department of Education of Jilin Province(JJKH20211083KJ)2020 International Cooperation Project of the Department of Science and Technology of Jilin Province(20200801001GH)。
文摘Oxygen evolution reaction(OER)is a bottleneck half-reaction in many important energy conversion processes(e.g.,water splitting),and one of the key issues lies to develop high-efficiency,cost-effective OER electrocatalysts.Rather than those popular extrinsic modulations of any catalysts with gradually degraded performance,we aim at the utilization of the intermediates offered from the undergoing OER as long-standing electrocatalysts.Herein,by inverted design,we extracted the bimetallic borides(FeCoB_(2))-derived intermediates metal borates in the OER,unlocking their potential as a selffunctionalized highly active catalytic phase in-situ formed on the metal boride surface for continuing OER operation.Mechanistically,the surface metal atoms are oxidized to oxyhydroxides,and the surface metalloids(B)are further transformed to the corresponding oxoanions to form metal borates.Such OER self-produced electrocatalyst exhibits a small overpotential of 295 mV at 10 mA/cm2 and its high catalytic activity lasts even after 200 h.Compared with FeCoB_(2),the catalytic activity of this electrochemically activated FeCoB_(2) is~7 times higher.The in-situ formed metal borate is dominatingly responsible for the obtained high catalytic activity.Such unique OER-produced self-functionalization surfaces of metal borates afford to greatly reduce the energy barrier of the continuing OER,thereby accelerating the reaction process.
基金Project supported by the National Natural Science Foundation of China (Nos. 20107004 & 20173038).
文摘Based on the thermokinetic theory, a novel thermokinetic research methodself-function regression method, which could be used to determine the kinetic parameters k1, k2 and k-1 of the complex reaction: B+ , ,was proposed in this paper. The kinetics of the reaction of ascorbic acid (H2A) with hydrogen peroxide was investigated at pH=57 and T=298.15 K, and the kinetic parameters k1, k 2 and k-1 were obtained with this method. The kinetics of the reaction was investigated in detail. The kinetic parameters of the oxidation of ascorbic monoanion (HA-) and ascorbic dianion (A2-) with hydrogen peroxide were 3.33×10-3 s-1and 25.48 s-1 at 298.15 K, respectively. The molar enthalpy change for the reaction was -554.64 kJ·mol-1 in phosphate buffer solution at pH 7 and at 298.15 K.
基金Innovation Team Program of Guangdong Province,Grant/Award Number:2020KCXTD038Key Technologies Research and Development Program,Grant/Award Number:2019YFA0705202+1 种基金National Natural Science Foundation of China,Grant/Award Numbers:12032007,31701296,62274027,81941001Chongqing Natural Science Foundation,Grant/Award Number:cstc2019jcyjzdxmX0028。
文摘As a multifunctional fluorescent nanomaterial, carbon dots (CDs) not only have small size, stable chemical properties, excellent photoluminescence characteristics, but also exhibit good biocompatibility and low toxicity. It has attracted considerable attention in the field of nanotechnology and biological science. CDs contain abundant functional groups on the surface, which not only retain part of the properties of raw materials, but also may have new photoelectric, catalytic, biomedical, and other functions. In this review, we systematically summarize the synthesis methods, modifications, optical properties, and main biological functions of CDs in recent years. The application of functionalized modified CDs in biological detection, biological imaging, photodynamic therapy, photothermal therapy, targeted therapy, drug delivery, gene delivery, protein delivery, and other biomedical fields is introduced. The latest progress of CDs with its own biomedical function in antioxidant, anti-pathogen, and disease treatment is summarized. Finally, we discuss some problems in the practical application of CDs and look forward to the future development trend of self-functional CDs combined with surface modification to achieve multimodal treatment of diseases.
